【作者】 张晓；

【导师】 谭国俊；

【作者基本信息】 中国矿业大学 ， 电力电子与电力传动， 2012， 博士

【摘要】 有源电力滤波器(APF)是用于动态抑制谐波和补偿无功的新型电能质量控制装置，与传统无源滤波器相比具有不受电网参数影响、动态响应快等优点而日益受到研究人员的重视。三电平有源滤波器与传统两电平APF相比可以大大提高系统的容量，补偿效果好，系统可靠性高。本文对三电平有源电力滤波器相关的关键技术进行了研究。APF双闭环矢量控制时，矢量定向角的观测是控制系统关键环节之一，定向角观测的准确性和快速性直接影响到APF最终的谐波补偿效果。传统电网电压锁相环检测电压定向角的参数设计较为复杂，本文提出一种APF电网侧虚拟磁链角度的改进观测方法，改进方法采用高通滤波器和新型坐标变换所组成的新型辨识算法，代替传统电网虚拟磁链观测中的纯积分环节，从而消除了积分初值及直流偏移量对磁链观测带来的误差。改进方法有效避免了电网高频谐波带来的影响，改善了APF电网虚拟磁链角的观测精度。仿真和实验验证了采用的新型辨识算法观测磁链角的可行性和优越性。补偿电流的检测是有源电力滤波器的关键技术之一，检测准确性和快速性对有源电力滤波器的补偿精度有决定性影响。本文提出一种改进的FBD谐波电流检测算法，利用虚拟磁链观测方法，通过电网虚拟磁链角与电网三相电压相位之间的关系重构出单位幅值的三相电压，从而省去了电网电压锁相环节。并在此改进的FBD谐波检测算法中采用两个低通滤波器来替代纯积分器，可以实现幅值和相角检测无偏差。APF系统具有多输入多输出，强耦合、非线性的特点，本文综合考虑了干扰抑制性能以及模型不确定性，提出了一种新型的H∞鲁棒控制策略。根据APF系统的数学模型，建立广义被控对象的状态方程，综合参数慑动以及外部扰动，利用粒子群优化算法进行参数整定和优化，通过求解黎卡提（riccati）不等式，得到所设计的控制器的解。仿真和实验证明了所提出的控制器可同时满足系统鲁棒稳定性和干扰抑制性能的要求。有源电力滤波器对电流内环的控制要求是快速性、鲁棒性和稳定性。本文设计了一种新型的变指数趋近律滑模控制器对有源电力滤波器进行控制。基于新型的变指数趋近律，开始时系统状态量以变速和指数两种速率趋向滑模面，当接近滑模面时，指数项趋近零，变速项起关键作用。在系统稳定过程中状态量趋向于零，有效地抑制了抖振。仿真和实验进一步证明了所提出的控制器的有效性，具有比鲁棒性更加优越的不变性，算法简单，易于工程实现。在有源滤波器应用系统的开发中，功率主回路的电磁兼容设计是重中之中。本文给出了一种基于有限元分析方法的平板母线设计思路，通过合理建模、优化寻优，可以获得理想的低电感平板母线。仿真和实测都证明了该方法的有效性。更多还原

【Abstract】 The active power filter (APF), as a dynamic harmonic suppression and reactivepower compensation apparatus, has gained more and more research attention due toits advantages such as anti-perturbation ability to the network parameters and fastdynamic response compared with the traditional passive power filters. Three-levelneutral-point-clamped inverters applied to APF not only increased the installedcapacity greatly but also improved the harmonic compensation performance andsystem reliability. This paper investigates the key techniques of the three-levelneutral-point-clamed inverter applied to APF.As for the APF double closed-loop space vector control, the observation of thespace vector orientation angle is a critical point. Whether the observation of theorientation angle is rapid and accurate directly affects the final harmoniccompensation performance of APF. For the traditional phase lock loop, the parameterdesign for detecting the voltage orientation angle is relatively complicated. And animproved observation method of detecting the virtual flux angle of the APF grid sideis proposed in the paper, which adopts a novel identification algorithm composed ofhigh-pass filters and novel coordinate transformation in place of the pure integrator inthe traditional grid virtual-flux observation, thus eliminating the virtual-fluxobservation errors brought about by the integral initial value and DC offsets. Theimproved method can effectively avoid the impact of grid high-frequency harmonicsand improve the accuracy of the observed grid virtual-flux angle. Simulation andexperiments demonstrate that the novel identification algorithm applied to flux angleis feasible and superior.Compensation current detection is one of the critical techniques for APF andwhether the detection is accurate and fast directly affects the compensation precision.An improved FBD harmonic detecting method is proposed in this paper, whichemploys the virtual-flux observation method and reconstructs the three-phase voltageof the unit amplitude by the relations between the grid virtual-flux angle and thethree-phase voltage actual angle, thus eliminating the phase lock loop. And besides, inthe improved FBD harmonic detecting method, two low-pass filters are adopted toreplace the pure integrator, which guarantees the amplitude and the phase angle of nodeviation.APF is characteristic of multi-input, multi-output, strong coupling and nonlinearity. Considering the disturbance attenuation performance and modeluncertainty as a whole, a novel H∞robust control strategy is proposed in this paper.According to the mathematical model of APF, state equations of the generalizedcontrolled target are established. And taking parameter perturbation and externaldisturbance into consideration, the particle swam optimization (PSO) algorithm isemployed for parameter tuning and optimization. By solving the Riccati inequality,the solution to the designed controller is obtained. Simulation and experimentsdemonstrate that the proposed controller meets the requirements of system robuststability and disturbance attenuation simultaneously.APF demands the inner current control loop of rapidity, robustness andstability. So a novel sliding mode controller is also proposed in the paper. Someimprovements are made to the exponential reaching law put forward by AcademicianGao Weibing and therefore a new variable-exponent reaching law is derived, whichmakes the system state variables approach to the sliding surface at the variable speedand the exponential speed in the beginning, and when the status point is close to thesliding surface, the value of the exponential component gets near to zero, and then thevariable speed component plays a key role. Chattering can be inhibited effectivelywhen state variables are infinitely close to zero in the process of system stabilizing.Simulation and experiments have demonstrated the effectiveness, simplealgorithm, easy engineering implementation of the proposed controller, and the moresuperior invariance to robust control aforementioned.In the devising stage of the practical system, to seek a solution to theelectromagnetic compatibility problem of the main power circuit is the most critical. Aflat-panel design idea based on finite element analysis is presented in the paper. Bymeans of appropriate modeling and optimization, the ideal low inductance flat-panelbus can be achieved. Both the simulation and field measurement demonstrate thevalidity of the method.更多还原